Large bearings
of outstanding quality

Wind energy

Laulagun Bearings has extensive experience in the manufacture of large bearings for wind turbines, an industry in which it has been involved since its start and which has seen significant development over the last few decades, largely due to increased demand for renewable energies for electricity generation. Both onshore and offshore turbines have been equipped.

Laulagun Bearings is one of the leading manufacturers of blade and yaw bearings for the wind energy industry. It has made over 30,000 large bearings to date.

Blade Bearing (or Pitch Bearing)

The blade bearing is mounted on the each blade root and enables blade turning, to adjust the angular position and optimize the power and aerodynamic performance and load control. Blade bearing is part of the main braking system of the machine and thus a safety component. In consequence, a reduced and constant friction torque value under load must be waranteed. On the other hand, when the bearing is not equipped with a by-pass system, it must withstand the lighting current passing through without damage.

Blade bearings are subjected to alternate and stochastic loads, during periods of small angle oscillating operation and long stationary periods.

The most usual bearing type used as blade bearing is “Double Row 8-point contact”.

There are two main types of drive systems:

Electric Drive. In this case, the required torque to turn the blade is given by means of a pinion and a gearbox mounted on the hub. The torque is transmitted through the teeth cut on the ring bolted to the blade root. Approx. 90% of the operation time, the pinion is acting on a small circular sector shorter than 10º. Therefore, a small number of teeth suffer the biggest number of contact cycles and loads and thus it is necessary a greasing system to assure an adequate lubrication such as a lubrication pinion accompanied by Microlubgear device.

Hydraulic Drive. The mechanical joint of one or two cylinders is connected to the blade root in order to provide the required torque to turn the blade. The maximum turning angle in service (flag position) is in between 90 and 100 degrees.

Yaw bearing

Yaw bearing enables angular realignment of the nacelle into the predominant wind direction. The yaw bearing is driven by several pinions and gearboxes mounted on the nacelle and distributed around the perimeter and meshing with the geared ring of the yaw bearing which is bolted to the tower.